Case-hardening compound.



I UNITED STATES PATENT oEEIoE.

PATRICK W. BBENNAN, OF PHILADELPHIA, AND MICHAEL MEEHAN, OF 'WILLIAMS- TOWN, PENNSYLVANIA.

CASE-HARDENING COMPOUND.

No Drawing.

Specification of Letters Patent. Application filed March 7, 1912. Serial No. 682,279.

Patented Aug. 2t), 1912 T 0 all whom. it m (1y concern.-

Be it known that we, PATRICK W. BREX- xxx and MICHAEL Mum-tax, citizens of the United States. residing at Philadelphia, in the county of Philadelphia, and \Villiamstown, in the county of Dauphin, respectively, both in the State of Pennsylvania. have invented new and useful Improvements in Case-Hardening Compound, of which the following is a specification.

Our present invention pertainsto the case hardening of articles of iron and other metals; and it consists-in a casd' hardening compound made up of the following ingredients, combined in the proportions stated, viz:

Cyanid of potassium (powdered) 2 ounces.

Bicarbonate of soda 1 ounce. Bicarbonate of potassium (powdered) .1 ounce. Bone dust ounce.

. jected to the action of the mixture until dark. The articleis then again subjected to the action of a slow fire and is heated to about a bright red, after which it is plunged in water.

Practical experience has demonstrated that the depth of the casehardening will depend upon the number of times the article of iron or steel is heated and then-rolled in the case hardening mixture;

Having described our invention, what -we claim and desire to secureby LettersPattent, is:

A case hardening compound comprising. cyamd of potassium, bicarbonate of soda, bi- V carbonate of potassium, and bone dust, sub

stantially as described and for the purpose specified.

In testimony whereof we have hereunto set-our hands in presence of two subscribing V witnesses.

Witnesses:

"' WM. BLANNING,

C. F. BLANNING. 

